var util = require("util");
function Base() {
  this.name = "base";
  this.base = 1991;
  this.sayHello = function() {
    console.log("Hello " + this.name);
  };
}
Base.prototype.showName = function() {
  console.log(this.name);
};
function Sub() {
  this.name = "sub";
}
util.inherits(Sub, Base);
var objBase = new Base();
objBase.showName();
objBase.sayHello();
console.log(objBase);
var objSub = new Sub();
objSub.showName();
// objSub.sayHello(); // TypeError: objSub.sayHello is not a function
console.log(objSub);
